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authorVladimir Zapolskiy <vzapolskiy@gmail.com>2011-09-21 09:26:44 +0000
committerDavid S. Miller <davem@davemloft.net>2011-09-28 13:41:50 -0400
commitf786ecba4158880f8cdc0ebb93e7d78e6c125449 (patch)
tree0291e9079912f41ad2dd67ffd609a554e98b7850
parent5dd17e08f333cde0fa11000792e33d8d39b5599f (diff)
connector: add comm change event report to proc connector
Add an event to monitor comm value changes of tasks. Such an event becomes vital, if someone desires to control threads of a process in different manner. A natural characteristic of threads is its comm value, and helpfully application developers have an opportunity to change it in runtime. Reporting about such events via proc connector allows to fine-grain monitoring and control potentials, for instance a process control daemon listening to proc connector and following comm value policies can place specific threads to assigned cgroup partitions. It might be possible to achieve a pale partial one-shot likeness without this update, if an application changes comm value of a thread generator task beforehand, then a new thread is cloned, and after that proc connector listener gets the fork event and reads new thread's comm value from procfs stat file, but this change visibly simplifies and extends the matter. Signed-off-by: Vladimir Zapolskiy <vzapolskiy@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/connector/cn_proc.c26
-rw-r--r--include/linux/cn_proc.h11
-rw-r--r--kernel/sys.c1
3 files changed, 38 insertions, 0 deletions
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index e55814bc0d06..77e1e6cd66ce 100644
--- a/drivers/connector/cn_proc.c
+++ b/drivers/connector/cn_proc.c
@@ -205,6 +205,32 @@ void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
}
+void proc_comm_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ struct timespec ts;
+ __u8 buffer[CN_PROC_MSG_SIZE];
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = (struct cn_msg *)buffer;
+ ev = (struct proc_event *)msg->data;
+ get_seq(&msg->seq, &ev->cpu);
+ ktime_get_ts(&ts); /* get high res monotonic timestamp */
+ put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+ ev->what = PROC_EVENT_COMM;
+ ev->event_data.comm.process_pid = task->pid;
+ ev->event_data.comm.process_tgid = task->tgid;
+ get_task_comm(ev->event_data.comm.comm, task);
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
void proc_exit_connector(struct task_struct *task)
{
struct cn_msg *msg;
diff --git a/include/linux/cn_proc.h b/include/linux/cn_proc.h
index 12c517b51ca2..d03612b196e1 100644
--- a/include/linux/cn_proc.h
+++ b/include/linux/cn_proc.h
@@ -54,6 +54,7 @@ struct proc_event {
PROC_EVENT_GID = 0x00000040,
PROC_EVENT_SID = 0x00000080,
PROC_EVENT_PTRACE = 0x00000100,
+ PROC_EVENT_COMM = 0x00000200,
/* "next" should be 0x00000400 */
/* "last" is the last process event: exit */
PROC_EVENT_EXIT = 0x80000000
@@ -103,6 +104,12 @@ struct proc_event {
__kernel_pid_t tracer_tgid;
} ptrace;
+ struct comm_proc_event {
+ __kernel_pid_t process_pid;
+ __kernel_pid_t process_tgid;
+ char comm[16];
+ } comm;
+
struct exit_proc_event {
__kernel_pid_t process_pid;
__kernel_pid_t process_tgid;
@@ -118,6 +125,7 @@ void proc_exec_connector(struct task_struct *task);
void proc_id_connector(struct task_struct *task, int which_id);
void proc_sid_connector(struct task_struct *task);
void proc_ptrace_connector(struct task_struct *task, int which_id);
+void proc_comm_connector(struct task_struct *task);
void proc_exit_connector(struct task_struct *task);
#else
static inline void proc_fork_connector(struct task_struct *task)
@@ -133,6 +141,9 @@ static inline void proc_id_connector(struct task_struct *task,
static inline void proc_sid_connector(struct task_struct *task)
{}
+static inline void proc_comm_connector(struct task_struct *task)
+{}
+
static inline void proc_ptrace_connector(struct task_struct *task,
int ptrace_id)
{}
diff --git a/kernel/sys.c b/kernel/sys.c
index 18ee1d2f6474..b3dfb76f8073 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1759,6 +1759,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
sizeof(me->comm) - 1) < 0)
return -EFAULT;
set_task_comm(me, comm);
+ proc_comm_connector(me);
return 0;
case PR_GET_NAME:
get_task_comm(comm, me);

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